The answer to 'furnace repair blowing cold air' is that there are several common causes, including a malfunctioning thermostat, a problem with the furnace's pilot light or ignition system, a clogged air filter, or an issue with the furnace's blower motor. Symptoms may include the furnace running but not producing warm air, or the air coming out of the vents being cold.
Some potential solutions include checking and replacing the air filter, resetting the thermostat, or relighting the pilot light. However, more complex issues like problems with the ignition system or blower motor may require the expertise of a professional HVAC technician. It's generally best to call a professional if you're not comfortable troubleshooting the issue yourself or if the problem persists after basic troubleshooting.